Tin Oxide Based Nano Electroceramics Obtained from Sol–Gel Process: The Modified of the Structural and Opto-Electrical Properties with the Al Doping

2018 ◽  
Vol 13 (10) ◽  
pp. 1460-1467
Author(s):  
Cihat Aydin
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Crystallite Size ◽  
Tin Oxide ◽  
Sol Gel ◽  
Control Surface ◽  
Al Doping ◽  
Al Content ◽  
Tauc Plot ◽  
Sol Gel Process

Nano electroceramic samples of undoped and Al doped SnO2 were synthesized by the sol–gel calcination process. The structural, morphological, electrical and optical properties of samples were characterized. X-ray diffraction analysis results confirm that all of the synthesized nanopowders are polycrystalline with a tetragonal structure. The crystallite size values of the prepared nanocomposites were calculated in the range of 21.32–34.33 nm. The values of crystallite size indicate that the prepared powders have nanostructure. The grain size and morphological parameters of the undoped and Al-doped SnO2 nanopowders calculated. AFM measurements suggest that Al dopants ratio could be an effect to control surface parameters of the SnO2 nanomaterials. The optical band gap (Eg) of prepared nanomaterials were calculated using Tauc plot method for the various atomic ratios of Al. The calculated Eg values for samples are found to be in the range from 3.51 to 3.69 eV. The electrical conductivity of undoped and Al doped Tin oxide nanopowders were carried out at the temperature range from 290 to 420 K. It demonstrates that the electrical conductivity at room temperature and the activation energy of samples increase with the Al doping. The obtained results suggest that the structural, morphological, optical and electrical properties of SnO2 based nanomaterials can be controlled and changed with Al content.

scholarly journals Bio-dielectric based on superconductors yttrium calcium barium copper oxide (YCaBa2Cu3O7−x ) from eggshell as calcium oxide source via sol-gel process

2021 ◽  
Vol 39 (3) ◽  
pp. 305-318
Author(s):  
Wipawadee Toumvong ◽  
Pornnita Chitcharoentaweechoke ◽  
Nuchnapa Tangboriboon
Keyword(s):  
Electrical Conductivity ◽  
Dielectric Constant ◽  
Electrical Properties ◽  
Copper Oxide ◽  
Room Temperature ◽  
Dielectric Material ◽  
Sol Gel ◽  
Barium Copper Oxide ◽  
Barium Copper ◽  
Sol Gel Process

Abstract Eggshell is a rich source of calcium that is a dielectric material used for doping in a superconductor. Yttrium calcium barium copper oxide (Y x Ca1−x Ba2Cu3O7) was prepared using the sol-gel process and fired at 900 °C or 1,000 °C. The stoichiometric ratio of the raw materials Y2O3:BaCl2:CuO:CaO was 1:2:3:1 based on the molar mass. The obtained YCaBCO had an orthorhombic crystal structure composed of distorted oxygen-deficient perovskite. The orthorhombic structure was unsymmetrical, providing a substantial increase in the physical electromagnetic properties of the superconductor. The YBCO-900-reference analyzed using an impedance analyzer in the range from 500 Hz to (1 × 106) Hz and at room temperature (27 °C) had the following values for capacitance, electrical conductivity, and dielectric constant ± standard error: 8,286.70 ± 28.49 pF, (3.60 ± 0.01) × 107 S/m, and 1,874.794 ± 6.446, respectively. The YCaBCO-900-eggshell (Y x Ca1−x Ba2Cu3O7) analyzed at 500 Hz at room temperature (27 °C) had high values for capacitance, electrical conductivity, and dielectric constant, namely, 8,540.10 ± 2.00 pF, (1.32 ± 0.00) × 108 S/m, and 1,988.540 ± 0.500, respectively. Furthermore, the YCaBCO-900-eggshell had electrical properties (capacitance, conductivity, and dielectric constant values) higher than those of YCaBCO-900-commercial grade measured under the same conditions. The YCaBCO-900-com grade had capacitance of 8,225.75 ± 0.73 pF, electrical conductivity of (1.40 ± 0.01) × 108 S/m, and dielectric constant of 1,874.59 ± 0.17, respectively. Therefore, eggshell is an alternative dielectric material useful for doping in yttrium barium copper oxide (YBCO) to form YCaBCO, thus causing an increase in its electrical properties. The obtained superconductor is a candidate that could be applied in many industries.

scholarly journals Synthesis and Characterization of Al-doped NiO Nanostructured Thin Films Elaborated by Solar Spray Pyrolysis Technique, for Photovoltaic Cells

2021 ◽  
Author(s):  
Abdelbaki NID ◽  
Lilia ZIGHED ◽  
Yacine AOUN ◽  
Bedreddine MAAOUI
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Spray Pyrolysis ◽  
Spray Pyrolysis Technique ◽  
Visible Region ◽  
Al Doping ◽  
Al Content ◽  
Doping Ratio ◽  
Nio Films

In this experimental work, pure nickel oxide and Al-doped NiO thin films have successfully been elaborated onto glass substrates by solar spray pyrolysis technique. The substrates were heated at around 450°C using a solar heater (furnace). The structural, optical and electrical properties of the elaborated Al-doped films have been studied at different atomic percentage ratios (0, 0.5, 1, 1.5 and 2 at. %). The results of Al-doped NiO films XRD patterns were, the formation of (NiO) phase under a cubic crystalline structure (polycrystalline) with a strong favored orientation along (111) plane were noticed at all sprayed films. When Al doping ratio reaches 1 at.%, an growth in crystallite size over 31.9 nm was obtained denoting the nano-structure of the product, which confirmed by SEM images. In addition, aluminum oxide Al2O3 was clearly observed at 1.5 at.% Al ratio. Otherwise, all thin films have a good optical transmission in the visible region of about 65%, the optical band gap energy decreased from 3.69 to 3.64 eV with increasing Al doping ratio. It is shown that the layer deposited with 0.5 at.% has less disorder with few defects. The investigation on electrical properties of elaborated thin films confirmed that the conductivity of NiO films was improved, after doping them with Al which affirms their p-type character of semiconductor. However, an addition of an excessive quantity of Al content causes the formation of Al2O3 which leads to a decrease in the conductivity. It is worth mentioning that the Al content of 0.5 at.% is the optimum ratio in terms of electrical conductivity and formation defect. Al-doped NiO can be used in various optoelectronic devices due to its good transparency and high electrical conductivity.

Gasochromic and electrical properties of Pt-nanoparticle-dispersed tungsten oxide thin films prepared by a sol-gel process

2012 ◽  
Vol 1400 ◽  
Author(s):  
Yuki Yamaguchi ◽  
Keishi Nishio ◽  
Tohru Kineri
Keyword(s):  
Thin Films ◽  
Electrical Conductivity ◽  
Electrical Properties ◽  
Sol Gel ◽  
Hydrogen Gas ◽  
Optical And Electrical Properties ◽  
Pt Nanoparticle ◽  
Gas Concentration ◽  
Sol Gel Process ◽  
The Relationship

ABSTRACTIt is well known that tungsten tri-oxide (WO3) exhibits electrochromic and gasochromic properties. When Pt-nanoparticle-dispersed tungsten oxide (Pt-WO3) is exposed to hydrogen gas, the optical and electrical properties of the Pt-WO3 change drastically. Consequently, it is expected that thin films of WO3 can be applied as hydrogen gas leakage sensors. In this study, thin films of Pt-WO3 were prepared on glass substrates using a sol-gel process. The optical and electrical properties of the films were evaluated. Amorphous and crystalline WO3 were easily obtained by changing the heat-treatment temperature. The ion diffusion coefficient of the film depended on the WO3 structure (i.e., whether it was amorphous or crystalline) because the density of amorphous WO3 is lower than that of crystalline WO3. Films with low crystallinity were found to have superior chromic properties to both those with high crystallinity and amorphous films. Thin films of Pt-WO3 prepared at 673K showed the largest change in optical transmittance and electrical conductivity when exposed to H2 gas compared with thin films prepared at other temperatures. When this film was exposed to 100% H2 gas, the normalized transmittance decreased rapidly (in less than 0.2 sec) from 100% to almost 50%. The optical absorbance of the film was dependent on the H2 gas concentration (mixed with N2 gas) in the range from 0.1 to 5% and the relationship between them was linear. The relationship between the electrical conductivity and hydrogen gas concentration (mixed with N2 gas) in the range from 100 to 10000ppm was also linear.

Study of the structural and electrical properties of PMNT 68/32 ceramic prepared by a sol–gel process

2005 ◽  
Vol 78 (4) ◽  
pp. 329-336 ◽  
Author(s):  
Pawan Kumar ◽  
O. P. Thakur ◽  
Chandra Prakash ◽  
T. C. Goel
Keyword(s):  
Electrical Properties ◽  
Sol Gel ◽  
Structural And Electrical Properties ◽  
Sol Gel Process
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